Recently, a high-density optical disk system (DVD) which has about 7 times higher recording density than the conventional CD has been proposed and many manufacturers have announced plans to market DVD players in 1996. The DVD is also expected to be used as a large-capacity peripheral memory for personal computers and it is assumed that a DVD drive will be compatible with conventional CDs, i.e., the DVD-ROM drive will be able to read CD-ROMs, as well as DVD-ROMs. We have developed a DVD/CD-compatible pickup head which permits reading of data from both DVDs and CDs by means of exchanging objective lenses. These two types of lenses are set on a common table, where two sets of flat coils are situated in order to exchange lenses. Experimental data show that our dual lens actuator head satisfies our preliminary design targets and performs as well as a single lens actuator.
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